Neutralizing Activities Against the Omicron Variant After a Heterologous Booster in Healthy Adults Receiving Two Doses of CoronaVac Vaccination

Safety and immunogenicity of full or half dose of COVID-19 booster vaccine after completion of two-dose inactivated and viral vector vaccines

Status

Active, not recruiting

Phases

Phase 4

Study type

Interventional

Source

TCTR

Registry ID

TCTR20210910002

Enrollment

200

Registered

2021-09-10

Start date

2021-09-14

Completion date

Unknown

Last updated

2026-08-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Thai individuals above 18 years of age. vaccine, booster, COVID-19, inactivated, viral vector

Interventions

This group received two dose CoronaVac vaccines as primed regimen and then boosted with one dose of inactivated vaccine (BBIBP).,This group received two dose CoronaVac vaccines as primed regimen and t

Active Comparator Biological/Vaccine,Active Comparator Biological/Vaccine,Active Comparator Biological/Vaccine,Active Comparator Biological/Vaccine

inactivated vaccine (BBIBP),viral vector vaccine (AZD1222),BNT162B2,mRNA-1273

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Inclusion criteria

Inclusion criteria: Healthy Thai individuals above 18 years Have never been infected with COVID-19

Exclusion criteria

Exclusion criteria: Immunosuppressed conditions

Design outcomes

Primary

Measure	Time frame
antibody response 1 month post booster dose IgG	—

Secondary

Measure	Time frame
safety within 7 days after vaccination self report incidence of adverse events	—

Countries

Thailand

Contacts

Public ContactYong Poovorawan

Chulalongkorn University

yong.p@chula.ac.th022564000

Outcome results

None listed

Source: TCTR (via WHO ICTRP) · Data processed: Aug 9, 2026